You mean the GameController class from the 1.x scaffold project, right?
Actually, the new "SPViewController" implements the same functionality right now. (Though it's now a "UIViewController" subclass.)
So, depending on what functionality you need, you can either subclass "SPViewController" -- or, if you need more Sparrow-related functionality, just create a new GameController class (a Sparrow Sprite) and let that be the root object of your Sparrow instance. You should be able to copy+paste most code from your old version over.